1. Field of the Invention
The present invention relates to a magnetic recording medium and production thereof. More particularly, it relates to a magnetic recording medium with improved durability and corrosion resistance and a method for the production thereof.
2. Description of Related Art
One method for producing a magnetic recording medium comprises applying a layer of a magnetic metal or metal alloy by vacuum deposition or sputtering on a substrate film, or bonding a ferromagnetic metal powder together with a binder component on the substrate film. Since the magnetic recording medium is vigorously slid against a magnetic head during recording or reproducing information, the magnetic layer tends to be abraded. Particularly, while the magnetic recording medium with the magnetic layer formed by vacuum deposition is suitable for high density recording, its friction coefficient with the magnetic head is so large that it is easily abraded or scratched. In addition, the deposited metal layer is gradually oxidized in the air, which results in a deterioration of the magnetic characteristics, such as the maximum magnetic flux density.
In order to improve the durability and corrosion resistance of the magnetic recording medium, it has been proposed to provide a protective layer on the surface of the magnetic layer. For example, Japanese Patent Kokai Publications (unexamined) Nos. 8882/1983 and 60427/1983 disclose a protective layer produced by plasma polymerization of a fluorine-containing organic compound or a silicon-containing organic compound, and Japanese Patent Kokai Publication No. 154643/1984 discloses the formation of a lubricant layer made of an organic compound having a carbon-carbon unsaturated bond on the protective layer produced by plasma polymerization.
The magnetic recording medium having either or both the protective and/or lubricating layers, however, does not have satisfactory durability and corrosion resistance, so that it is quickly abraded by sliding on the magnetic head.